1. Field of the Invention
The invention relates to a coupling for hoses or the like for media under pressure.
2. Description of the Background Art
Couplings of this type, so-called quick couplings, are well-known and exist in many different forms. An important area of application for such couplings is to make possible rapid connection and disconnection of a tool operated by pressure medium to/from a hose for supplying pressure medium. During use of the connected tool in a workplace, the hose coupling and the hose are often drawn along when the tool is moved. When this takes place, the hose coupling may get caught on unevennesses in the ground, which may lead to unintentional disconnection. To reduce the risk of this happening, the locking sleeve has been designed in such a manner that it must be both rotated and displaced in the axial direction in order for disconnection to be possible. It has been found, however, that such a construction may also lead to unintentional disconnection. This is because, when the nipple is rotated, for example by the connected tool being rotated during performance of the work, the balls in the ball lock can function like planet wheels in a planetary gear and in this way bring about rotation of the locking sleeve. It is subsequently only necessary for the locking sleeve to be displaced axially for disconnection to take place.
The object of the invention is to produce a coupling of the type referred to in the introduction, which improves the security against unintentional disconnection by eliminating the problem described above.